The invention relates to a rotary-anode X-ray tube, comprising an anode disc which is mounted on a rotary shaft and which comprises a basic body of graphite, and also relates to a method of manufacturing an anode disc for such an X-ray tube.
German Auslegeschrift No. 1,764,042, which corresponds to U.S. Pat. No. 3,539,859, describes such an X-ray tube wherein the basic body consists of pressed and sintered graphite. In comparison with anode discs having a basic body of molybdenum or a molybdenum alloy, an anode disc of graphite offers the advantage that it is particularly light, has a thermal capacity and also a high thermal emissivity.
It is a drawback of this known X-ray tube that the connection between the anode disc and the rotary shaft, which is driven by a motor, fractures after a relatively short operating time. Because of the low mechanical strength and brittleness of pressed and sintered graphite, mechanical loading--for example tangential loading during starting and stopping of rotation--will cause fracturing of the connection.